docs: def _random_edge_iterator(graph, n_edges: int) -> Iterable[Tuple[BaseEntity, BaseEntity, int, Mapping]]:
      """Get a random set of edges from the graph and randomly samples a key from each.
  
      :type graph: pybel.BELGraph
      :param n_edges: Number of edges to randomly select from the given graph
      """
      edges = list(graph.edges())
      edge_sample = random.sample(edges, n_edges)
      for u, v in edge_sample:
          keys = list(graph[u][v])
          k = random.choice(keys)
          yield u, v, k, graph[u][v][k]